INCOME TAXES - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2011	Nov. 30, 2010	Nov. 30, 2011	Nov. 30, 2010
Income Taxes [Line Items]
Effective income tax rate	29.20%	30.80%	29.60%	30.60%
Income tax Examination years			During the six months ended November 30, 2011 we settled the U.S. federal income tax examination for fiscal years 2007 and 2008.
Unrecognized tax benefits, reduction resulting from settlement of U.S. federal income tax examination			$ 1.4
Tax assessments from non-U.S. jurisdictions, possible additional payments upon final resolution			1.2
Unrecognized tax benefits	4.3		4.3
Unrecognized tax benefits which, if recognized, could affect the effective tax rate	3.4		3.4
Accrued interest and penalties related to unrecognized tax benefits	$ 1.5		$ 1.5